1. Field of the Invention
The present invention relates generally to in-rush current limiting circuits, and more specifically, the present invention relates to low dissipation in-rush current limiting circuits.
2. Background Information
In certain applications of electronic circuits, it is desirable to control the in-rush current that flows into a circuit when a supply voltage is applied. Examples of such applications are in DC-DC conversion (or rectified AC) applications where a power conversion unit is connected to a DC source (or rectified AC) supply and where the power conversion unit includes a large capacitor at the input to the power converter. The in-rush current limiting circuit function is to regulate the current drawn from a power source providing the DC supply voltage to the power converter circuit. Without the use of an in-rush current limiting circuit, the current that charges the input capacitor of the power converter would be uncontrolled leading to a very high in-rush current potentially causing damage to connectors and other components of the power converter and power source equipment.
Applications for in-rush current limiting circuits are normally required to operate at high efficiency and therefore any in-rush current limiting circuit configuration allowing improved efficiency is highly desirable.